Performance areas, such as stages, are typically open spaces designed to accommodate a variety of configurations—background scenery, risers, seating, props, etc. As such, the sound quality is less than desirable, especially with respect to an audience. To improve sound quality for an audience, a shell is constructed on the stage, or in the performance area, as a curved, hard surface to reflect sound toward the audience. The shell itself is designed to absorb as little sound as possible. Shells, otherwise called acoustic shells, are utilized in a variety of performance applications including any application that benefits from passive sound amplification. Acoustic shells can be removable such as by rolling panels away, flying them into a flyspace, or both.